Phosphate ester amine salts useful as fuel detergents and anti-icing agents

ABSTRACT

HYDROCARBON SUBSTITUTED ALKYLENE POLYAMINES WHICH ARE PARTIALLY NEUTRALIZED WITH MONO- OR DIALKYL PHOSPHATES ARE TAUGHT FOR USE IN FUELS AS DETERGENT, ANTICORROSIVE AND DEICING AGENTS. THE HYDROCARBON SUBSTITUENTS ARE FREE OF AROMATIC UNSATURATION AND ARE FROM ABOUR 30 TO 300 CARBON ATOMS. THE ALKYLENE POLYAMINES HAVE FROM 2 TO 6 NITROGEN ATOMS.

United States Patent 3 702,757 PHOSPHATE ESTER AMINE SALTS USEFUL AS FUEL DETERGENTS AND ANTI-ICING AGENTS Envel- Melunedbasich, El Cerrito, Calif., assignor to Chevron Research Company, San Francisco, Calif. No Drawing. Continuation-impart of application Ser. No. 817,288, Apr. 16, 1969, which is a continuation of abandoned application Ser. No. 621,796, Mar. 9, 1967. This application Feb. 3, 1971, Ser. No. 112,478

Int. Cl. Cl1/18, 1/22, N26 US. CI. 44-58 Claims ABSTRACT OF THE DISCLOSURE Hydrocarbon substituted alkylene polyamines which are partially neutralized with monoor dialkyl phosphates are taught for use in fuels as detergents, anticorrosive and deicing agents. The hydrocarbon substituents are free of aromatic unsaturation and are from about 30 to 300 carbon atoms. The alkylene polyamines have from 2 to 6 nitrogen atoms.

CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation in part of applica tion Ser. No. 817,288, filed Apr. 16, 1969, which was a continuation of application Ser. No. 621,796, filed on Mar. 9, 1967, both now abandoned.

BACKGROUND OF THE INVENTION Field of the invention Demands on fuel performance go far beyond the fuel acting in a satisfactory manner as a power source. Additives are employed in fuels to provide corrosion protection during storage, handling and transportation, as well as to provide cleansing or detergency in the combustion engine, particularly in the carburetor or other areas through which the fuel may pass.

Also, additives are included in the fuel to prevent icing in the carburetor during winter months. The ice is formed by the refrigerating effect of evaporation of gasoline, condensing moisture in the atmosphere and causing stalling, particularly during idling.

Additives employed in the fuels must not only perform their required function, but must not interfere with the performance of the fuel and engine, must be compatible with other additives in the fuel, and not create auxiliary problems, such as water tolerance.

Description of the prior art Hydrocarbon substituted alkylene polyamines have been found effective detergents in fuel, such as diesel fuels and gasoline. See copending application Ser. No. 538,571, filed Mar. 30, 1966, now abandoned. Amine salts of alkyl acid phosphates wherein the hydrocarbon monoamine is of from 6 to 24 carbon atoms have been reported as fuel additives, providing anti-icing and antirust performance. See US. Pat. No. 3,228,758, issued Jan. 11, 1966.

SUMMARY OF THE INVENTION It has now been found that long chain hydrocarbon substituted alkylene polyamines having at least two amino nitrogen atoms and partially neutralized with alkyl phosphate esters, not only provide excellent detergency, but are also effective anti-icing and anticorrosion agents. The alkylene polyamines will generally be of from 2 to 6 nitrogen atoms having alkylene groups of from 2 to 6 carbon atoms, more usually of from 2 to 3 carbon atoms and having from 1 to 2 long chain hydrocarbon substituents. The hydrocarbon substituents will generally be of from 3,702,757 Patented Nov. 14, 1972 DESCRIPTION OF THE PREFERRED EMBODIMENTS For the most part, the compositions of this invention are relatively high molecular weight branched chain hydrocarbon N-substituted alkylene polyamines having a molecular range of from 450 and preferably 560 to an upper molecular weight of up to 10,000, more usually up to 5,000 and preferably up to 3,500, partially neutralized with a monoor dialkyl phosphate ester, wherein the alkylene polyamine has from 2 to 6 nitrogen atoms, more usually of from 2 to 5 nitrogen atoms. The preferred hydrocarbon substituted alkylene polyamines are polyisobutylene alkylene polyamines having from 1 to 2 polyisobutylene groups per alkylene polyamine and from 2 to 5 nitrogen atoms and an average molecular weight in the range of about 450 to 3,000 more usually 450 to 1,500 for the individual polyisobutylene group.

For the most part, the compositions of this invention are within the following formula:

0 R.H,-1+1l(N U) ,NH) -z{H0I -OA] The above symbols are defined as follows:

x-a number of from 1 to 2 (frequency averaging between 1 to 2) y-an integer of from 1 to 5 z-at least 1 and up to an amount equal to percent of the titratable amine nitrogen 1 Ualkylene of from 2 to 6 carbon atoms, more usually alkylene of from 2 to 3 carbon atoms Rhydrocarbon radical relatively free of aromatic unsaturation of from about 400 to 5,000 molecular weight. Aan alkyl group of from 8 to 24 carbon atoms Qhydrogen or an alkyl group of from 8 to 24 carbon atoms, which may be the same or different than A 1 0.5 stasis. 535E333. i s 5.53323 1. ifio fiifiifitfiiii tlon (toluenezisopropanol: water50:45: 5 by volume) and potentiometrlcally titrated with 0.1 N hydrochloric acid, using a Calomel vs. glass electrode (Pt) in a Sargent automatic titrator, model D.

Preferred compositions will generally have the following formula:

0 R'a w-mn (NU'),'NH: allHQ-i -OA The above symbols are defined as follows:

x'-1a nlugnber of from 1 to 2, more usually of from about ya number of from 1 to 5, more usually from 1 to 4 z 'a number in the range of l to y, more usually in the range of 1 to (y-1) R'a branched chain aliphatic radical of from about 400 to 3,000 molecular weight, more usually of from about 450 to 1,500 molecular weight A'-an alkyl group of from 10 to 20 carbon atoms Q'-an alkyl group of from 10 to 20 carbon atoms or hydrogen Uan alkylene group of from 2 to 3 carbon atoms Preferably, a mixture of monoand diester is used, that is, B is half hydrogen and half alkyl.

The phosphate salt is prepared by determining the equivalent weight of the hydrocarbon substituted alkylene polyamine by hydrochloric acid titration (as described above) and then adding the requisite amount .of phosphoric acid ester to the hydrocarbon substituted alkylene polyamine either neat or in a suitable solvent, e.g., a hydrocarbon medium. Preferably, a liquid hydrocarbon fuel will be used, and the composition prepared as a fuel concentrate. The reaction may be carried out at room temperature and does not require any special conditions or precautions.

The hydrocarbon substituted alkylene polyamines which find use have the following formula:

wherein the symbols are as defined previously.

Illustrative hydrocarbon substituents may be aliphatic or alicyclic and generally free of aromatic unsaturation. The hydrocarbon radical may be a polymer of olefins of from 2 to 6 carbon atoms (if ethylene is used, the ethylene will be generally copolymerized with an olefin of at least 3 carbon atoms) or may be derived from naturally occurring products of relatively high molecular weight, e.g., naphthenic bright stock or neutral oils. Illustrative hydrocarbon substituents are polyisobutylene, polypropylene, poly-4-methylpentene-l, etc.

The alkylene polyamines are illustrated by ethylene diamine, diethylene triamine, tetraethylene pentamine, 1-3- propylene diamine, l-2-propylene diamine, tetramethylene diamine, dipropylene triamine, etc. While not included in the above formulas, piperazine derivatives may also find use. These piperazine compounds are normally found with alkylene polyamines, since they are formed concurrently during some commercial preparations of alkylene polyamines. Illustrative piperazines which may find use are N-(2-aminoethyl)piperazine, and N,N-di(2-aminoethyl) -piperazine.

The phosphoric acids which find use have the following formula:

wherein the symbols have been defined previously.

Illustrative of the various phosphate esters are monodeeyl phosphate, didecyl phosphate, didodecyl phosphate, ditridecy phosphate, monotridecyl phosphate, octyl decyl phosphate, decyl dodecyl phosphate, etc. As previously indicated, the diester alkyl groups may be the same or different. Moreover, preferably mixtures of monoand diesters will be used, when the mole ratio of the monoto the diester will be in the range of about '1 8.0-1.2.

The following examples are offered by way of illustration and not by way of limitation.

EXAMPLE I Into a reaction flask was introduced 1,580 g. of a 75 percent active solution of polyisobutenyl chloride (approximately 1,100 molecular weight, 1.2 moles), 494 g. (4.8 moles) of diethylene triamine and 300 g. of butyl alcohol. A nitrogen atmosphere was provided and the mixture heated at 135 C. for 5 hours while the solvent was distilled over. At the end of this time, the reaction mixture was taken up in 800 ml. of toluene, the mixture heated to 75 C. and 105 g. of 95 percent alcohol and 400 g. of water added. The mixture was allowed to cool, the phases separated and the aqueous phase discarded. The Washing procedure was repeated three times. The organic phase was then distilled by slowly heating the solution to 123 C., taking water and toluene overhead. The residue Weighed 1,801 g. The active portion as determined by! nitrogen analysis was 55.25 weight percent. Titration with 0.103 normal hydrochloric acid (assuming only two nitro-i gens are titratable) indicated the solution was 49.7 percent active. To an aliquot of this solution was added a sufficient amount of a 1:1 mole mixture of mono and ditridecyl phosphate to provide a 1:1 mole mixture of the lpolyisobutenyl diethylene triamine and the mixture of phosphate esters.

A number of compositions were prepared similarly which will be reported in the following tables.

The compositions of this invention can be used in a variety of hydrocarbon fluids, such as lubricating oils, fuels, etc., whenever the presence of small amounts of water create corrosion problems. However, the compositions of this invention find particular use in fuels, in which they not only provide anti-corrosion, but also detergency and anti-icing. Illustrative fuels include diesel fuels, gasoline, kerosene, etc.

Depending on the use, it is found that as little as 2.5 parts per million (p.p.m.) of the phosphate salt composition will be effective for corrosion inhibition, although generally at least about 5 and not more than about parts per million will be used for corrosion inhibition. For detergency, and anti-icing, use of at least 15 parts per million and generally not more than 0.1 weight percent will be used. Most frequently, excellent results will be obtained with concentrations of the additive of from about 100 to 5,000 p.p.m.

The additives of this invention are particularly useful with volatile fuels having Reid vapor pressures above about 9. These are generally winter grade gasolines employed in northern areas where the Reid vapor pressure of the fuel is between about 9 and 13.5. D

The additives of this invention are compatible with the other fuel additives which are included in fuels. Illustrative of such additives are antiknock agents, e.g., tetramethyl lead or tetraethyl lead, lead scavengers such as alkyl and aryl halides, additional anticorrosion agents, deposit modifiers, oxidation inhibitors and metal deactivators, carburetor detergents, etc.

Nonvolatile light lubricating oil, such as petroleum spray oil, is also a suitable additive for the gasoline compositions used with the additives of this invention and ts use is preferred. These oils are believed to act as a carr er for the active compositions of this invention and assist in removing and preventing deposits. They are employed in amounts of 0.05 to 0.5 percent by volume, based on the final gasoline composition.

The effectiveness of the compositions of this invention as rust inhibitors was tested as follows. Both the exemplary composition of Example I and a composition having 2 moles of the mixed phosphate esters per mole of polyisobutenyl diethylene triamine were tested in a particularly difficult fuel as far as preventing rust: a gasoline having an unleaded octane of about and rich in both aromatics and reformate. The testing procedure followed ASTM D 665-60, using synthetic sea water and the additive concentration was 30 p.p.m. The ratings are based on a range of from 1 to 7, 7 being completely rusted and 1 being no rust. While the base fuel gave a rating of 7, the two additives, the one with the 1 mole and the other with the 2 moles of mixed phosphate ester, each gave a rating of 1. (There was a trace of rust with the additive having only 1 mole of the mixed phosphate ester.)

In order to demonstrate the use of the compositions of this invention as antistalling agents, a number of compositions was tested in a lab engine test as follows.

The carburetor which is used is designed for the 1965 Plymouth 225 cubic inch engine and is employed with a Plymouth L-head 230 cubic inch engine. The carburetor is thermally isolated from the engine and during tests is maintained in a warmed up condition by a controlled heating element. When equilibrium temperature has been established in the carburetor, the engine is started and accelerated to 2,400 r.p.m., no load, Where it is operated for 30 seconds. The engines speed is then dropped to idle (525-550 r.p.m.) for 15 seconds. As soon as the engine TABLE I Moles] amine of Additive phosphate Average Determiamlne 1 ester 1 stalls nations III 8. 2 3 2 7. 5 3 3 7. 3 3

l II= Polyisobutenyl diethylene triamine (polyisobutenyl of about 570 mol. weight; percent N, 6.25); III= Polylsobutenyl trlethylene tetramine (polyisobutenyl of about 950 mol. Weight; percent N 5 .11 I 1:1 mole mixture of monoand ditrldecyl phosphate.

In order to demonstrate the excellent detergency of the compositions of this invention, the following test was carried out. Using a Plymouth L-head engine, a clean glass throttlebody is run on base fuel for 1 hour with all blowby gases ducted to the carburetor inlet and with a rich air-fuel ratio. The conditions are as follows: jacket temperature, 160 F.; oil temperature, approximately 130 F.; engine speed, 500 r.p.m. and accelerates to 2,000 r.p.m. five successive times every 7 mins.; load, none. This is followed by running the engine on the additive containing fuel for 4 hours with no blowby gases ducted to the carburetor and with the normal air-fuel ratio. A comparison of the throttle body at the end of the first 1 hour period and at the end of the run with the additive containing fuel is determined as the percent of deposits removed by the additive fuel.

Usually, the run is carried out at least 4 times and the results reported as an average of all the runs.

The samples used were the parent amine and the base amine partially neutralized with a 1:1 mole ratio of monoand di(tridecyl) phosphate. The results reported are the percent improvement of the phosphate salt over the parent amine, that is, the difference in percent removal of deposits. The following table indicates the results:

Additional detergency tests were carried out as follows. A single-cylinder CFR engine equipped with throttle was employed. The operating conditions were as follows:

Jacket temperature, F. 212 Oil temperature, -F. 150480 Intake air temperature, F. 95 Ignition timing, BTC 15 Intake manifold vacuum, in. Hg. 15 Fuel/air ratio 0.07 Run length, hr. 12

Speed, r.p.m.

The evaluation was based on the deposits which form on the intake valve. At the end of the test, oil and grease were carefully removed from the valve stem. Combustion deposits were removed with a wire brush and the valve weighed. The underhead of the valve was then washed with hexane until the hexane ran clear and the valve was then dried in an oven at 200-2 40" F. After cooling, the valve was weighed, all deposits were removed and the tare weight of the valve obtained. Three samples were prepared employing commercially available gasoline and 100 p.p.m. of the compositions being tested plus 400 p.pm. of a solvent refined neutral oil, 21.9 API gravity, viscosity at 100 F., 1685 SUS.

Compound IV is Duomeen T (N-alkyl propane-1,3- diamine, and alkyl derived from tallow acid). Compound V is polyisobutenyl substituted tetraethylene pentamine (polyisobutenyl of about 1,000 viscosity average molecular weight). Compound VI is polyisobutenyl ethylene diamine (polyisobutenyl of about 1,400 viscosity average molecular weight). The three compounds were percent neutralized, based on the base number of the amine and the acid number of the acid with a 1:1 mole ratio of monoand di(tridecyl) phosphate. The following table indicates the results.

TABLE III Valve wt. of deposits. mg.

Unwashed Washed Compound:

IV 119 90 91 56 VI 53 29 Base fuel 90 Unleaded gasoline (F-l 86.7).

Examples 4-7 In a manner similar to that used to test Compounds I-III above, four other phosphate ester amine salts were tested in a. single cylinder engine. The operating conditions were as follows:

Jacket temperature, F. 212 Oil temperature, F. 150-180 Intake air temperature, F. 95 Ignition timing, BT C 15 Intake manifold vacuum, in. Hg 15 Fuel/air ratio 0.07 Run length, hr. 12 Speed, r.p.m. 1800 The tests were carried out at a concentration of p.p.m. in commercial gasoline and using 400 p.p.m. of a solvent refined neutral oil, 71.9 API gravity, viscosity at 100 F., 1,685 SUS.

Compound VII was a polyisobutenyl substituted ethylene diamine (polyisobutenyl of about 560 viscosity average molecular weight).

Compound VIII was Duomeen T (N-alkyl propane-1,3- diamine, the alkyl being derived from tallow acid).

Compound IX was a polyisobutenyl substituted tetraethylene pentamine (polyisobutenyl of about 1,000 viscosity average molecular weight).

Compound X was a polyisobutenyl substituted ethylene diamine (polyisobutenyl of about 640 viscosity average molecular weight).

The four compounds were 90 percent neutralized, based on the base number of the amine and the acid number of the acid with a 1:1 mole ratio of monoand di(tridecyl) phosphate. The following table shows the results obtained.

It is evident from the above table that at 100 ppm. the Duomeen T salt is not efiective in preventing deposition of deposits on the valve. By way of contrast, the higher molecular weight polyamines are quite effective in reducing the deposit formations.

It is evident from the above results that the compositions of this invention provide a broad spectrum of enhanced properties to fuels. Not only is excellent detersive action retained-surprisingly detergency is improved but also corrosion inhibition, particularly rust inhibition, is provided, as well as anti-icing activity. Furthermore, the compositions are compatible with the other additives normally in a fuel.

As will be evident to those skilled in the art, various modifications on this invention can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

I claim:

1. A phosphate amine salt having the formula:

wherein x is a number averaging from about 1 to 2, y is an integer of from 1 to 5, z is at least 1 and up to and including an amount equal to 90 percent of the titratable amine nitrogen, U is alkylene of from 2 to 6 carbon atoms, R is an aliphatic or alicyclic hydrocarbon radical of from about -60 to 5,000 molecular weight, A is an alkyl group of from 8 to 24 carbon atoms and Q is hydrogen or an alkyl group of from 8 to 24 carbon atoms.

2. A composition according to claim 1, wherein Q is a mixture of hydrogen and alkyl.

3. A composition according to claim 1, wherein at is a number of from about 1 to 1.6, y is a number of from 1 to 4, z is a number in the range of .1 to (y-l), R is a branched chain aliphatic radical of from about 560 to 3,000 molecular weight, A is an alkyl group of from 10 to 20 carbon atoms, and Q is hydrogen or an alkyl group of from 10 to 20 carbon atoms.

4. A composition according to claim 3, wherein Q is a mixture of hydrogen and alltyl.

5. A composition according to claim 3 wherein R is polyisobutenyl having a molecular weight of about 1,400.

6. A composition according to claim 3 wherein R is polyisobutenyl having a molecular weight of about 1,000.

7. A composition according to claim 3 wherein R is polyisobutenyl having a'molecular weight of about 560. 8. A composition according to claim 3 wherein R is polyisobutenyl having a molecular weight of about 640.

9. A liquid hydrocarbon fuel composition having in an amount effective for anti-icing, detergency and anticorrosion, a composition according to claim 1.

10. A composition according to claim 5, having an amount of from 0.05 to 0.5 percent by volume of a nonvolatile light lubricating oil.

11. Phosphate amine salt of polyisobutenyl substituted diethylene triamine, wherein said polyisobutenyl group is of 1,100 molecular weight neutralized with a 1 to 1 mole mixture of monoand ditridecyl phosphate.

12. Phosphate amine salt of polyisobutenyl substituted diethylene triamine, wherein said polyisobutenyl group is of 1,400 molecular weight neutralized with a 1 to 1 mole mixture of monoand ditridecyl phosphate.

13. Phosphate amine salt of polyisobutenyl substituted diethylene triamine, wherein said polyisobutenyl group is of 1,000 molecular weight neutralized with a 1 to 1 mole mixture of monoand ditridecyl phosphate.

14. Phosphate amine salt of polyisobutenyl substituted diethylene triamine, wherein said polyisobutenyl group is of 560 molecular Weight neutralized with a 1 to 1 mole mixture of monoand ditridecyl phosphate.

15. Phosphate amine salt of polyisobutenyl substituted diethylene triamine, wherein said polyisobutenyl group is of 640 molecular weight neutralized with a 1 to 1 mole mixture of monoand ditridecyl phosphate.

References Cited UNITED STATES PATENTS 2,863,742 12/1958 Cantrell et al 4458 3,035,905 5/1962 Keller 44--DIG 4 3,425,815 2/ 1969 Rosenwald et al. 4472 DANIEL E. WYMAN, Primary Examiner W. J. SHINE, Assistant Examiner US. Cl. X.R.

44-72, DIG l, DIG 4; 252-392; 260-924, 925 

